A silencer of this type is disclosed in U.S. Pat. No. 3,361,227. The silencer described and illustrated in said patent is particularly suitable for silencing the exhaust sound from a combustion engine. Because the efficiency of combustion engines is of considerable importance, a balance must be sought between silencing of the sound and impedance of the gas flow. Silencing of pans of the audio spectrum which are not covered by the silencer in question is provided by additional silencers connected up- or downstream. The effort involved in this type of construction is, on the one hand, justified by the reduced loss which occurs as a result and, on the other hand, possible because, especially in vehicles, a long length is available for the installation of such silencers.
Silencers of this type are unsuitable for compressed air compressors. In the prior art silencers lined with sound-absorbent material are used for compressed air compressors. Silencers of this type have the advantage that a broad audio spectrum can be covered by a single silencer. In this context efficient silencing is more important than the impedance of the gas flow because it is possible to compensate for losses in flow in a simple manner, for example by increasing the power of the motor which drives the compressor. However, the use of silencers lined with glass wool or another absorbent material has the disadvantage that silencers of this type can no longer be cleaned such that they meet the demands of the foodstuffs industry and hospitals. Frequently the minimum requirement for these sectors is that the silencers can be sterilised of flushed with a liquid disinfectant.